How To Keep A Greenhouse Warm

How To Keep A Greenhouse Warm 1

There are a few ways on how to keep a greenhouse warm; you can use a compost, heater, ventilator, insulator, and many more. Well, greenhouses are created to extend the time for gardening all through different seasons.

That is possible because the building is kept heated by solar radiation, making it warm even in winter. The sunlight passes through the roof to heat the ground and plants inside. In a nutshell, the thermal energy that is trapped inside the greenhouse keeps it warm.

However, not all can afford to build professional-grade greenhouses that can effectively keep itself warm no matter the weather. Hence, they need some other means to keep it insulated.


Keeping Your Greenhouse Warm

In this article, we will discuss some of the alternative ways how to keep a greenhouse warm. So without further ado, let’s get started!


#1 Use compost 

One of the best ways on how to keep a greenhouse warm is by using compost. The composition of organic material in making compost can generate large amounts of heat. That heat is generated due to the bacteria present in the material as it breaks down.

So before the cold weather comes around, you need to put compost on your garden beds. Doing so can greatly help in keeping the plants warm, especially its critical part that is the roots. Ensure to add a thick layer because bacteria like to stay in a warm environment. Two to three inches thick would be enough.


#2 Add a heater if necessary

There are a lot of natural ways on how to keep a greenhouse warm, yet it is still a good idea to add a heater. A compact size heater would be enough to get rid of the chill during the night or even during the winter season.

If you are concerned about the carbon dioxide that it may produce, don’t be, because the plants will consume those gasses and eventually convert it into oxygen during photosynthesis.

One example of heaters that you can use is KlimaHeat. With this, you no longer need to wait for it to give off heat – it will automatically warm up after switching it on.


#3 Circulate the air

Even if you are already using a heater, it might not be enough to keep the greenhouse warm, especially when extreme cold weather hits. Rather, ensure that the air inside the room is evenly warmed. Because if not, there is a high possibility of hot and cold patches.

At worst cases, the temperature readings of the room will be inaccurate. Placing the probe at one corner will give different results than the other.

So to avoid this from happening, you have to keep the air mixed well with the help of heat circulators or circulator fans. It would not cost much to get this, yet it will help you a lot in keeping the climate of your greenhouse.


#4 Ventilation

As we all know, plants use carbon dioxide and transform it into oxygen. They also release moisture and energy-rich compounds. So if you do not keep the greenhouse ventilated, there will be a high chance that your plants will grow in a humid environment.

Or worse, there will be a depleted amount of carbon dioxide that they can use. In this case, organisms such as fungus, mildew, and mould might grow and become a threat to your plants.

To prevent that from happening, you just have to open the vents of your greenhouse periodically. Doing so will freshen the air. But take note, you need to close them when night comes to ensure that the chill will not come through.


#5 Add insulation

Bubble wrap is not only used to protect fragile packages. But you can also use this to add a layer of insulation to your greenhouse. Attach it onto its interior walls to minimize heat loss. This will also serve as a barrier that greatly helps in blocking the winter drafts.

Although the traditional bubble wraps are sufficient. You might as well want to opt for bubble wraps that are specially manufactured for horticultural purposes. These products have large bubbles and are also UV stabilized. You can find this at any garden centers.


#6 Add a thermal mass

Another thing that you could do to warm your greenhouse is by adding thermal mass. This option is one of the easiest to do while at the same time incurring least cost. The thermal mass will absorb the heat in the daytime, and when the chilly night comes, it will release the heat.

Through this, the temperature can increase by 1-2 degrees. That may sound a little, but it can make a significant difference. The most common way of making a thermal mass is by placing some filled water containers inside.

If your greenhouse is a bit small, you can use 1-gallon plastic jugs. Fill it with water for about three-quarters full and place it throughout the room. The heat absorption can even be increased by painting the jugs with black. But you may also add black food color to the water.



Do not let your plants freeze outdoors during cold weather. Keep them warm and alive inside the greenhouse. And by applying the aforementioned tips on how to keep a greenhouse warm, you can further keep them heated. Now, you can surely ensure food supply all year round.

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